The present disclosure describes systems and techniques relating to determining a real-time position of a mobile device.
A mobile device such as a smart phone or tablet computer is often built from multiple devices, which can include a radio chip coupled with an antenna, a general purposes processor, and inertial and/or MEMS (Micro-Electromechanical Systems) sensors. In addition, a mobile device can run one or more location-aware applications that are programmed to perform location-based tasks such as store finding and transit routing. Location-aware applications can determine a position of a mobile device using various technologies, such as satellite-based positioning systems (e.g., the Global Positioning System (GPS)) and ground-based cell phone systems or wireless network systems (e.g., WiFi).